This invention relates generally to a tapping system and more particularly to a tapping system for use with a rotating-spindle machine.
Throughout this work, terms "coaxial" and "coaxiality" shall be used to refer to tools, devices and various geometries which share the same centerline or major axis. In the drawings, this characteristic will be portrayed as alignment on a centerline or, if viewed from above, as essentially concentric geometries, i.e., sharing an identical center.
For years, machinists have threaded holes by initially boring or drilling the desired chamber and then inserting and either machine or manually rotating a thread-cutting tap into the chamber. This basic method, though simple, has definite shortcomings in the age of precision machining.
First, machine driven tapping usually produces a rougher thread than does manual or hand tapping. This is caused by the tendency of the very hard steel of the tap to burnish the surface or thread faces of the material being worked. Conversely, hand tapping generally produces a much cleaner and smoother thread because the machinist progresses slowly, reverses the tapping motion and is literally able to "feel" his way through the work.
Another shortcoming of the basic method, and a disadvantage of its manual aspect, is that true coaxial alignment of the thread axis with that of the desired bore is rarely obtained. Needless to say, if true precision tapping is to be achieved, coaxial misalignment must be eliminated. An idealized tapping system would embody the sensitized human skill with the precision of an accurate, stable machine. I feel that I have achieved these highly desirable characteristics in this hand tapping system while, at the same time, I have defeated other onerous or precision-destroying facets of the aforementioned basic tapping methods.
It is therefore an object of the present invention to minimize the time normally consumed in moving from a drilling operation to a tapping one.
Another object of this invention is to make the manual tapping operation easier by eliminating any requirement for hand(s) removal from the tap wrench, while giving the machinist a sure and more comfortable grip with a clear line-of-sight to the tap and work piece.
Another object of this invention is to provide a simple, sound means of inserting and securing a tap into the wrench without the use of other tools and while avoiding the coaxial misalignment mentioned earlier. In addition to being easily insertable, there should be a corresponding ease of removal.
Another object of this invention is to coaxially align the tap, with the bore or hole to be threaded, with utmost precision.
Another object of this invention is to provide means for moving the tap away from the work piece and temporarily securing it in a ready-to-use position in order to facilitate movement of the work piece and immediate reuse of the tap.
Another object of this invention is to provide an inherently safe design so that, should the spindle machine inadverently be turned on, the invention will not become an additional hazard.
A further object of this invention is to provide a manual tapping system which is usable with a stable shaft, hollow or solid, which has affixed to it a clamping means such as a chuck or collett. Such shafts would include, but are not necessarily limited to the spindles of drill presses, vertical millers, lathes, and the like.
Objects and advantages of this invention are set forth herein but by no means circumscribe the breadth of the invention nor the concepts and applications derivable from the disclosed principles. Practice with this invention will make the stated advantages clear while one versed in the machinist or tool design art may infer the more subtle by referring to the Summary, Drawing Descriptions, Preferred Embodiments and Claims as hereinafter described.